Chronic diseases require administering of medicaments or drugs according to a predefined time schedule in order to keep the concentration level of a pharmaceutically active substance within given margins. Many medicaments require administration by way of injection. Therefore, patients administering the medicament in self-medication typically make use of syringes or syringe-like drug delivery devices. Such devices should be universally applicable and should be operable even by persons without formal medical training.
Moreover, such devices, like pen-type injectors, should provide accurate, precise and reliable setting of a dose and subsequent dispensing of the respective amount of the medicament. Typically, the medicament to be dispensed and injected is provided in a disposable or replaceable cartridge, such as a vial, an ampoule or a carpule comprising a piston slidably disposed therein to become operably engaged with a piston rod of a drive mechanism of the drug delivery device. The drive mechanism is adapted to apply thrust to the cartridge's piston in a distal direction in order to built-up a respective fluid pressure, which in turn induces dispensing of the liquid medicament via a dispensing or distal end of the cartridge being typically in fluid connection with a piercing element like an injection needle.
It is generally of importance, that the patient strictly follows a given prescription schedule. However with patients that already got used to the medicament for a long time or patients that suffer side effects of a chronic disease and which may be physically or mentally impaired, compliance of the prescription schedule is sometimes sub-optimal. Since a large variety of existing, e.g. disposable drug delivery devices is implemented all-mechanically, it is also rather difficult for an attending physician to control, whether the patient strictly follows the given prescription schedule.
For instance document WO 2011/042540 A1 discloses a safety injection system having a multi-dose delivery module and a removable cap configured to cover a needle on a distal end of the dose delivery module. Said safety injection system further comprises a time lock operatively connected to the cap and the multi-dose delivery module. This way, an automatic lockout feature is provided so that certain users will be effectively prevented from accidental over medication. However, such an automated lockout feature always requires, that the patient or user of the device always returns the removable cap back onto the distal end of the dose delivery module after an injection procedure has been accomplished.